Why RAID 5 Stops Working In 2009

Lally Singh recommends a ZDNet piece predicting the imminent demise of RAID 5, noting that increasing storage and non-decreasing probability of disk failure will collide in a year or so. This reader adds, "Apparently, RAID 6 isn't far behind. I'll keep the ZFS plug short. Go ZFS. There, that was it." "Disk drive capacities double every 18-24 months. We have 1 TB drives now, and in 2009 we'll have 2 TB drives. With a 7-drive RAID 5 disk failure, you'll have 6 remaining 2 TB drives. As the RAID controller is busily reading through those 6 disks to reconstruct the data from the failed drive, it is almost certain it will see an [unrecoverable read error]. So the read fails ... The message 'we can't read this RAID volume' travels up the chain of command until an error message is presented on the screen. 12 TB of your carefully protected — you thought! — data is gone. Oh, you didn't back it up to tape? Bummer!"

Re:Carefully protected?

[sholsinger]

Next they'll want to unionize. At that point you've lost everything.

Re:Carefully protected?

[DrVxD]

Oh come on. Do you have 12TB of home data? Seriously? And if you do, it's not that hard to have another another 12TB of external USB drives at some relatives place.

Not all of us have relatives, you insensitive...[URE]

Confessions of a reformed RAID addict

[rs79]

You get your first RAID controller from a trusted friend. "Here" he says "try this" and hands you a Mylex board. It has a 64 bit bus and 3 SCSI LVD connectors. Oooh. That looks fast. So you start ebaying drives, cables, adapters, more controllers, the inevitable megawatt power supply and you mess around with raid 1, raid 0 raid 1+0 and raid 5. Suddenly every system falls prey to RAIDMANIA; eventually for yourself you build a system with 3 controllers, with 3 busses each and a drive on each one of 9 busses. With a controller for swap, one for data and one for the system will Windows now be fast? Yeah, sorta. Those drives sure are quiet - from a click-click busy noise perspective, NOT from a "sounds liks a jet airplane when running" perspective. Heat is an issue, too.

http://rs79.vrx.net/works/photoblog/2005/Sep/15/DSCF0007s.jpg [vrx.net]

But oh my are the failure modes spectacular.

I just use a laptop now and make several sets of backup DVDs or just copy to spare drives. I love RAID to death. But it's really only marginally worth the effort in the real world. But if you need fast, OMG.

Re:Carefully protected?

[WhatAmIDoingHere]

"Or you can burn a pile of DVDs and hide them throughout the woods."

Patent that right NOW, I think we've got a winner to replace RAID-5.

Re:Carefully protected?

[Facegarden]

Buying a computer system you cannot afford to properly use is crazy. Yes, some people are crazy, and those crazy people are going to lose data, but there's no sense in defending it.

Well, i guess i'm crazy, i have 3TB of space on my home PC, and no way to back it all up offsite. I do have some important folders from one drive automatically copy to another drive periodically, so if one drive dies the other will be okay, but if i lose them both or the place burns down or i get a nasty virus, it's all going to hell.
Most of my space is taken up by pirated... err... backed up... HD movies. And porn, lots of porn.
Either way, i'm not too worried if i lose that, it's just the things i back up i really care about.
The thing is, i was going to RAID 3 of the drives into a secure 1TB array, but now i hear all these issues with RAID and i worry that it may be WORSE than just copying over the files periodically. I want a DROBO but those are expensive as hell.

This article has inspired me to look into Tape Backup but i worry that it's not cost effective (i haven't looked yet).

I should fill up some tapes with a few hundred gigs of porn, write "confidential" on them, and stash them in a bag, under some bush, across the street from HP near my apartment. I'm sure some curious person would come looking, only to discover their contents and wonder why the hell someone went to all that trouble....

God i'm strange.
-Taylor

Re:RAID doesn't protect against your worst enemy

[Kleen13]

(though it's been running since '04 without any problems, and my HD health monitors show it in good shape)

Oh man.... you didn't just say that out loud did you???

Re:RAID doesn't protect against your worst enemy

[Junior J. Junior III]

My data backup scheme is to steganographically embed my entire filesystem into nude pictures of Sarah Palin, and then upload them to usenet.

Re:Carefully protected?

[binarylarry]

That's why serious IT people use Fedex.

Punch Cards

[vldragon]

I used to use the old punch card system to backup my data. Sure it takes a while but it was totally worth it... Until one day while attempted to move the many boxes fully of carefully sorted cards I fell down the steps and the cards went everywhere. I learned from that mistake and started writing all everything down on paper... Lot's o' 1's and 0's, my hand hurt.. A lot. But there was a fire at my off site :( sot I had to resort to the ultimate old school back up. A chisel and a rock... a really really big rock.

Comment removed

[account_deleted]

Comment removed based on user account deletion

Re:RAID doesn't protect against your worst enemy

[Renderer of Evil]

That's why I chisel all my data (ones and zeros) onto stone tablets. In a few years the pile of stones will be taller than Everest. :)

And in a thousand years some bearded guy will discover couple of those stones, come down the mountain and will base a religion around it. These things are cyclical.

Re:RAID doesn't protect against your worst enemy

[Samantha Wright]

And look what happened? Netcraft is already half way to confirming the demise of alt.binaries!

Raid 5 - Kills Drives Dead(tm)

[fortapocalypse]

RAID???!!! Aaaaaaah! (Drive dies.)

Re:RAID doesn't protect against your worst enemy

[SatanicPuppy]

Lets hope he discovers some porn this time...

Re:RAID doesn't protect against your worst enemy

[tkw954]

rm -r *

That doesn't work for me. Try

sudo rm -rf /*

Re:RAID doesn't protect against your worst enemy

[Waffle Iron]

The Egyptians found a way to preserve their message over thousands of years, surely we can come up with something. :)

And they would have saved future generations from vast amounts of confusion and effort, if they'd only been a little more diligent backing up their pyramid construction HOWTO files.

Re:RAID doesn't protect against your worst enemy

[Anonymous Coward]

You leave RMS out of this!

Re:Carefully protected?

[camperdave]

Keep in mind that Flash cells are memory arrays and as such are susceptible to ionizing radiation that can and will flip bits.

That's okay. We'll just gang them together in a RAID 5 configuration.

Re:Carefully protected?

[darkpixel2k]

The company BOTH cares about their data AND can't afford a proper backup system.

In this case, linux has one last resort for you:
sudo apt-get install bible

darkpixel@hoth:~$ bible
bible: Debian/BRS Release 4.18, $Date: 2005/01/23 11:29:22 $
Hit '?' for help.

-snip-

bible(KJV) [Gen1:1]> ec3:6

Ecclesiastes 3

6 A time to get, and a time to lose; a time to keep, and a time to cast away;
bible(KJV) [Ec3:6]>


Mainly pay attention to that whole '...and a time to lose' part.

Re:Carefully protected?

[0100010001010011]

It's ok, he just works for Verizon.

Re:RAID doesn't protect against your worst enemy

[Alarindris]

#%^@%!#$!!!! The second one works!!

Re:Carefully protected?

[MrNaz]

Must be the admin for a Windows server.

Re:Carefully protected?

[dbIII]

I'll tell you that I was pretty serious when Fedex put a forklift tine through the front of a server they were shipping.